Young bald eagle dies when wind downs nest

May 11, 2007|By Sarah Ottney, American News Writer

Brown County lost one of its eight known bald eagle nests last week when the dead cottonwood tree that held the nest apparently blew over, said Bill Schultze, a wildlife biologist with the U.S. Fish and Wildlife Service at Sand Lake National Wildlife Refuge. The nest - containing at least one eaglet, which was killed - was a mile south of U.S. Highway 12 between Aberdeen and Groton, in the James River bottom, and was clearly visible from the road, Schultze said. Gordon Nelson, who lives in Groton and looked at the nest every day on his way to work in Aberdeen, said the nest was there when he went to work on the morning of April 30 - but not when he returned home that night. Nelson, who teaches HuntSafe classes with retired Game, Fish and Parks conservation officer Bill Antonides, told Antonides the nest was down, who then passed the information on to Schultze. Antonides and Schultze went out to check on the nest on May 3, at times wading through chest-deep water to get to the site. They found the 2- to 3-week-old eaglet a few feet from the downed nest, partially eaten by a predator. Because eaglets cannot fly until they are 10 to 12 weeks old, the chick probably died in the fall, Schultze said. However, it's possible it survived the fall and was attacked and eaten later, Antonides said. If there was a second chick in the nest, it might have been carried off by a predator, Antonides said. It's also possible another chick was crushed under the nest, Schultze said. Bald eagle nests can weigh a ton or more because eagles return to the same nest year after year and keep adding to it, Schultze said. The downed nest was 5 to 6 feet in diameter and 4 to 5 feet deep, he said. The raptor rehabilitation program at the Bramble Park Zoo in Watertown was ready to take a live chick if one had been found, Schultze said. “That young of a bird, I don't know if we would have been able to save it, but they were willing to try,” Schultze said. Not a surprise: Antonides said it was not a surprise that the nest came down. “For some reason, quite a few eagles seem to pick dead cottonwoods,” Antonides said. “And they're standing in water at least part of the year, so they're rotting. Then they build a 1-ton nest on them. And then the South Dakota winds. So it's just a matter of time. I'm frankly surprised it lasted as long as it did.” Wildlife officials knew that if the nest came down in the spring, eaglets would be lost, Antonides said. However, interfering with a nesting tree is not only illegal, but would have been bad for the species as a whole. “It hurts to lose a nest, but this is nature's way of teaching them where to build nests and where not to,” Antonides said. “Nature is a strict teacher, but the survival of the species depends on the ability of the birds to select good nesting sites. A short-term loss can make things better in the big scheme of things.” A close call: The same nest survived a close call five years ago when a controlled burn fire got out of control and came near the grove of trees. “It maybe even blackened them a bit, but it didn't burn them down,” Antonides said. “I was out there that day to see that that fire didn't take down the tree with the nest in it.” Antonides said he went out to see if there was any way equipment could be brought in to protect the tree. There wasn't, he said - too much water and downed timber - and it was pure luck that the wind changed and the fire missed the tree. Nest produced seven chicks since 2001: Schultze said the tree was the first containing a bald eagle nest to blow down in Brown County that he knew of. The downed nest, which was the southernmost nest in the county, was first observed in 2001, Schultze said, and seven eaglets have fledged from the nest since then. The first successful bald eagle nest in Brown County since the 1880s was confirmed in 1993, Schultze said. The first successful nest in South Dakota was confirmed in 1992. Bald eagles were recently moved off the endangered species list, and are now considered threatened. Brown County's seven known remaining nests are all active, and probably have young birds in them, Schultze said. Interesting finds: Antonides said there was “an amazing variety” of food inside the downed nest, including a Ross' Goose, several species of duck, pheasant feathers, northern pike, carp and a clam shell. “(The clam shell) still baffles me a little bit,” Antonides said. “I don't think clams are ordinarily part of an eagle's diet, but maybe it was just shiny and he picked it up.” Another interesting thing found in the nest, Antonides said, was part of an arrow shaft, which he assumes the eagles picked up to use as nestbuilding material. What's next: Nelson said he noticed an adult eagle at the site for two or three days afterward, looking for the nest. Schultze said he expects the parents to hang around the area for a while, but they won't lay any more eggs this year. He said they will probably start rebuilding the nest this fall or winter, most likely in the same general area. There was nothing Antonides could do to save the nest this time, but he said he hopes the eagles learned their lesson and will build in a safer location - a live tree - next time. To report a possible nest, or any concern with a nest or eagle, call Sand Lake refuge at (605) 885-6320 or GF&P at (605) 626-2391.